Motor vehicles such as automobiles, trucks and the like generally include a relatively simple, planar, frame structure which supports the engine, drive train and wheels. This frame also supports a body of the vehicle, which is typically fabricated from a number of support pillars which are retained upon the frame and have sheet metal body panels affixed thereto. The assembly of such vehicular bodies is fairly complex and requires specializing tooling and fixtures to enable the placement and welding of the various posts and panels.
The automotive industry is now considering using space frames in the construction of motor vehicle bodies. Space frames have previously been employed in the construction of aircraft, racing cars, and other high performance motor vehicles. A space frame comprises a rigid cage which defines the body of the vehicle and operates to support body panels and other structural elements. Space frames provide a rigid, lightweight, high strength structure which increases the crashworthiness of the vehicle. Space frames for specialty applications such as aircraft and performance vehicles are typically fabricated from welded components; however, such construction is not generally practical for high volume production motor vehicles. Consequently, the industry is looking for other methods for fabricating relatively inexpensive, high strength space frame structures. In one approach, specially designed connectors are employed to join tubes, bars, rails or other such frame members in a precise geometrical relationship so as to assemble the space frame. Space frames of this type are shown, for example, in U.S. Pat. Nos. 6,412,857; 6,276,111; 6,282,790; 5,458,393 and 5,209,541. One problem limiting the use of such technologies is the fact that each particular vehicle style will require a plurality of differently configured connector members. Such connectors must be relatively high in strength, and have precise geometries. Hence, such connectors are typically fabricated from metals or other such high strength materials. This unduly complicates the use of such space frame systems and greatly increases their cost.
As will be explained hereinbelow, the present invention provides a space frame system which utilizes connector members fabricated as composite bodies. The connectors of the present invention are very high in strength, yet are relatively easy to fabricate as high precision items, in large volumes, and at relatively low costs. As a consequence, the present invention provides a practical, low cost, readily reconfigurable space frame system. These and other advantages of the present invention will be apparent from the drawings, discussion and description which follow.
A frame system for a motor vehicle includes a plurality of frame members, each having a connector socket defined therein. The frame system further includes at least one connector. The connector has an outer profile configured to engage the sockets of two of said plurality of frame members so as to connect the frame members in a fixed angular relationship. The connector is a composite body comprising a core member and an exterior body which covers at least a portion of the core member and defines at least a portion of the outer profile of the connector. In specific embodiments, the core and exterior body are fabricated from different materials, and in one particular instance, the core is metal and the exterior body is a polymeric material.
The core may be elongated along the linear axis and the exterior body may cover substantially all of the length of the core, or it may cover only a portion of the length of the core. In some instances, a portion of the core is exposed upon or projects from a surface of the exterior body. The system may include auxiliary connectors configured and operable to retain the connector and frame member in a joined state. In yet other instances, either the frame member or the connector may have a connection feature associated therewith. The connection feature may comprise a mechanical connector such as a raised boss, a locking tooth, or the like, or it may comprise a body of adhesive.
Also disclosed herein is a method of assembling a frame structure for a motor vehicle using the system of the present invention.